We seek to continue a postdoctoral training program at the University of California, San Francisco that will train social, behavioral, and physician scientists to address the problems of AIDS prevention in the next era of the epidemic. Significant developments have occurred in the past several years that are altering AIDS prevention and research. The new, highly anti-retroviral therapy has brought both the promise of longer survival and a number of new problems. Post-exposure prophylaxis, now being studied as possible prevention tool, could potentially help or hinder the spread of HIV. These developments have brought hope to the fight against AIDS, but they also underscore the need for continued training in primary and secondary prevention of HIV disease that responds to the new ethical and behavioral. The UCSF program, called Traineeships in AIDS Prevention Studies (TAPS), is uniquely positioned to address these new challenges. We build on an excellent track record. Since 1989, the TAPS program has trained 42 postdoctoral fellows, 31 of whom have finished training and gone on to excellent positions in academic institutions and departments of public health and to an outstanding overall record of publication and research activity (see Table 8). In the past 4 years 8/18 trainees (44%) are ethnic minorities (1 African American, 3 Latino/as, 2 American Indian, 2 Asian). The program is housed at the Center for AIDS Prevention Studies (CAPS), an extremely productive research environment. CAPS provides trainees with common space, a computer network, a library, and easy access to a wide range of productive researchers from different disciplines as well as many regularly scheduled lectures, seminars, discussion groups, and peer reviews. A 5-yea renewal grant will make it possible to complete the training of the 12 trainees who will participate in the last year of the current award and to admit an average of 4 new trainees each year. Trainees will complete an MPH at UC Berkeley if they do not already have the degree of its equivalent; take the ORACLE course at UCSF in Research Methods, Clinical Epidemiology, and outcome Research; participate in weekly TAPS seminars; complete at least one significant research project;; teach; make presentations at national and international meetings; write at least one grant proposal; and submit several papers for publication.